Two Australian scientists who have paved the way for solar thermal power plants worldwide have been honoured with Australia Day medals. A world powered by solar energy is inevitable according to two distinguished scientists being honoured this Australia Day. Dr Graham Morrison, Emeritus Professor of Mechanical Engineering at the University of New South Wales and Dr David Mills, formerly a Senior Research Fellow at the University of Sydney, have been awarded Member of the Order of Australia medals for their services to science in the field of applied physics, particularly in the research and development of renewable energy and solar thermal technologies. "There really is no choice. The energy supplies that we have currently got, coal and gas, we have only got for another 100 years - that is the timespan of our grandchildren," says Morrison. "There is no question the transition to solar power has to happen, it is just a matter of how quickly do we make it happen." It is a sentiment that Mills agrees with, adding that wind power will most likely play a role in combination with solar in the world's future energy mix.
Dr Mills has calculated that solar and wind alone could be used to power the entire United States. He says that similar conclusions have been made for Australia. "It is hard to find two other more apt energy sources than solar and wind at this moment...I think they will be the heavy-load bearers for the future." Both Morrison and Mills have had illustrious careers in the field of solar thermal technology and have played a significant role in making power generation from solar thermal energy a commercial reality. One of their most significant achievements has been the development of the compact linear fresnal reflector technology which has now been used in solar thermal energy plants across the world.
The technology works by using flat mirrors that follow the path of the sun to reflect solar radiation onto a series of pipes positioned overhead. The pipes are filled with pressurised water which absorbs the heat and is converted to steam for power generation. The technology was used in Australia's first large-scale solar thermal plant in the Hunter Valley region of New South Wales where it was tacked onto an existing coal-fired power station in the early 2000s. That project attracted so much international attention that Morrison and Mills relocated to the United States to take advantage of the large amount of investment money being offered — funds that could not be matched in Australia.
The company they founded, Ausra Inc, received more than $130 million in venture capital and went on to build a four-megawatt plant in California and a 44-megawatt plant in Kogan Creek, Queensland, and it is currently building a 100-megawatt plant in India. While Morrison and Mills have since sold Ausra Inc, Morrison says that interest in solar thermal power is still rapidly increasing. "The solar thermal power industry has gone from really very little ten years ago to there now being around 20 large-scale solar thermal power plants across the world. The rate of growth is certainly going to keep increasing," he says. Morrison and Mills join a number of others being honoured this Australia Day for their services to environmental research and conservation.